• Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

You are not logged in You are logged out of this journal. Log In

Iterative algorithms for computing the shape of a hard scattering object: Computing the shape derivative

J. Acoust. Soc. Am. Volume 116, Issue 2, pp. 1002-1008 (2004); (7 pages)

Stephen J. Norton

Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6200

Full Text: Read Online (HTML) | Download PDF | Buy PDF (US$30) | View Cart
The problem of determining the shape of an acoustically hard scattering object from remote scattering measurements is considered. An iterative approach is used to find the object shape that minimizes the mean-squared difference between a set of actual and predicted scattering observations. A crucial task in this minimization is the computation of the “shape derivative,” or functional gradient, of the mean-square error with respect to the object’s shape or boundary. The shape derivative tells us how to update the object’s shape to reduce the mean-square error at each iteration. If, for example, the object’s boundary is parameterized with N variables, a brute-force approach to computing the shape derivative using finite-differences would require a minimum of N+1 forward solutions per iteration. We show how the shape derivative can be computed with just two forward solutions: one ordinary forward solution and a suitably constructed adjoint solution. This approach is independent of N and is not only far more efficient, but numerically less error prone, than finite-difference schemes for computing derivatives. © 2004 Acoustical Society of America.

© 2004 Acoustical Society of America

RELATED DATABASES

To view database links for this article, you need to log in.

KEYWORDS and PACS

PACS

  • 43.60.Rw

    Remote sensing methods, acoustic tomography

  • 43.60.Pt

    Signal processing techniques for acoustic inverse problems

ARTICLE DATA

History
Received 25 Aug 2003
Accepted 20 May 2004
Revised 18 May 2004

PUBLICATION DATA

ISSN

0001-4966 (print)  

For access to fully linked references, you need to log in.

For access to citing articles, you need to log in.



Close

close